In this MOD 11 counter, it counts 0 to 10. i.e from 0000 to 1010, then it repeats itself. For 4 bits, 4 counters are required. Here -ve edge triggered T flipflop is taken.
4 Bit Asynchronous Counter using JK Flip-FLop
Instructions
Set both buttons to off (RED). Now reset the sequencer and turn on button 1 and 2 (set to GREEN).
Button 1 controls the data fed to the displays.
OFF = Clear all displays ON = Programmed message
Button 2 controls the clock.
To change the message, dump the core or reset the EEPROM and rewrite the suitable data for the 16-Segment Displays. If the new message contains lesser or more letters/numbers to show, make suitable changes to the Sequencer and change the number of displays used.
3 Bit Asynchronous Down Counter
Two bit Asynchronous up counter that counts from 00 to 11 and back.
4 bit Asynchronous counter
Experiment 4 Synchronous and Asynchronous Counters